Today, we improve the things we make. The
University of Houston's College of Engineering
presents this series about the machines that make
our civilization run, and the people whose
ingenuity created them.

Let me tell you about a
strange human rhythm. It has to do with improving
the things we make. Things like accuracy and
efficiency improve exponentially in time -- as long
as the only real limit to improvement is our
inventive capacity.

Power-plant efficiencies are now at a point where
human ingenuity can't do much more for them. Now
they're up against the laws of physics. But the
first engines, back in the 1700s, were far less
than one percent efficient. They gave only one unit
of work for every 300 units of heat in the fuel
they burned.

That's far less than any physical limit. So, for
over a century, steam-engine efficiencies doubled
every thirty years.

You get the same story with mechanical clocks. The
first ones lost or gained about a half hour a day.
For the next 600 years, clock accuracies doubled
every 30 years.

We've doubled the speed of cars and trains every 30
years since we built the first ones in the late
1700s. The racing cars on the Utah Salt Flats are
still increasing speed at that rate.

That was true for every technology we started
before 1840. An odd animal insistence runs in the
way we change our machines. Of course 30 years is
evocative. It's one generation. It's a typical time
that any of us works directly in a field.

In 1840 the doubling rule changed. We
institutionalized technology. We set up R & D
labs. We created a new breed of professional
engineers and scientists. When we did, everything
sped up. But now it follows a new kind of 30-year
doubling rule.

Thirty years after 1840, we were quadrupling
quality every generation. Sixty years later, we
were improving it eight-fold in 30 years. After
1840 we started doubling the exponent of
improvement. Now the pace of change is absurdly
fast. Today, the quality of new technologies
doubles in months.

So I look at that 30-year rhythm and wonder.
Somehow, it's built into our bones that something
has to double every generation. It's unconscious.
It's inexorable. The inventive mind seems to be
animal instinct as much as volition.

Wars don't alter rates of inventive change.
Economics and kingly edicts don't alter it. Those
things touch production -- but never invention.
Invention flows from our inner being. It is a
powerful river that cannot be dammed or deflected.
I really believe that it's the way we insist on
life. Invention is the primary means by which we
rage against equilibrium and death.

I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.